A new study has found that chronic sleep deprivation can suppress the body's immune system.

Jan. 27 (UPI) -- Researchers from the University of Washington Medical School studied 11 pairs of identical twins to learn the effects of sleep deprivation on the immune system.

Blood samples were taken from the sets of identical twins with different sleep patterns and showed that the twin who got less sleep had a depressed immune system compared to their sibling.

"What we show is that the immune system functions best when it gets enough sleep," Dr. Nathaniel Watson, co-director of the UW Medicine Sleep Center at Harborview Medical Center and lead author of the study, said in a press release. "Seven or more hours of sleep is recommended for optimal health."

Researchers used twins in the study because genetics make up 31 to 55 percent of sleep duration, with behavior and environment making up the rest.

The study examined the effects of long-term short sleep duration under normal, "real world" conditions as opposed to a sleep lab, and found that chronic sleep deprivation shuts down the immune response of circulating white blood cells.

"The results are consistent with studies that show when sleep deprived people are given a vaccine, there is a lower antibody response and if you expose sleep deprived people to a rhinovirus they are more likely to get the virus," Watson said. "This study provides further evidence of sleep to overall health and well-being particularly to immune health."

Watson collaborated with Dr. Sina Gharib, director of UW Medicine's Computational Medicine Core at the Center for Lung Biology, on the study.